Hotspot in LAN

Hello I have the following problem. LAN connects to the Internet through RB750. it is running the server hotspot. when you turn hotspot disappears periodically ping between certain computers on your network. If you turn off the hotspot, the connection is restored. Please help me.
Sorry for my english)

The router has nothing to do with traffic between clients on a subnet behind one of its routed ports.

Post your network topology and configuration.

after changing the “Address Pool” in the settings Hotspot server to “none” problem has stopped.